Natural Family Planning, Part III

Picking up where we left off*, Fertility Awareness Methods (FAMs) work by preventing insemination (or fertilization). You identify the fertile period of the monthly cycle (with the aid of fertility indicators), and then you either abstain from sexual intercourse (periodic abstinence) or you use a back-up method during that time.

Fertility Indicators (FIs)

A quick word about fertility indicators (FIs): they are indirect or direct. Some examples of indirect FI are cervical mucus or position, basal body temperature, etc. Direct FIs are ultrasound visualization of ovulation, and blood or urine levels of sex hormones. Because direct fertility indicators are hard to incorporate into a birth control method (imagine lugging an U/S machine or a phlebotomist around all day long), most FAMs use indirect indicators. Only Persona uses direct ones (urine hormone levels).

Failure Rates

Overall, FAMs have a 1st year failure rate of 25% with typical use, and from 1% to 9% with prefect use. The efficacy of the methods in this group depends on two things:

1) Ability to accurately identify the fertile days of the menstrual cycle.

Direct fertility indicators identify the fertile days of the cycle more accurately than indirect ones. Most FAMs use indirect fertility indicators. For these, older methods identifying and tracking a combination of fertility indicators offers better pregnancy protection vs. relying on only one indicator.

2) Ability, or willingness, to either abstain from sexual intercourse (natural family planning) or to use a barrier method during the fertile period.

The best way to use a FAM is to not have sexual intercourse during the fertile period. (Actually, the safest way to use FAMs is to abstain from sexual intercourse from the start of the menstrual cycle, until the end of the fertile period. This is sometimes referred to as the Post-ovulation method, and it is the most effective method. The 1st year failure rate is 1%, with perfect use.)

FERTILITY AWARENESS METHODS (FAM)

a) Calendar Method

Rhythm (Ogino-Knaus)

Standard Days Method (SDM)

CycleBeads

b) Basal Body Temperature (BBT) Method

(Bioself 110/Mini-Sofia, LadyComp/BabyComp, Cyclotest-2)

c) Ovulation Method

Billings Method (Cervical Mucus)

Creighton Model

TwoDay Method

d) Cervical Changes Method

e) Sympto-Thermal Method

f) Personal Hormone Monitoring Method

Persona

A brief review of the individual methods:

a) Calendar Method

Rhythm (Ogino-Knaus)

Standard Days Method (SDM)

CycleBeads

With the Calendar method you attempt to calculate the start and the end of your fertile period, by tracking the length of your past menstrual cycles. The length of the past menstrual cycles is the indirect fertility indicator. This method is based on the 1930s theories of Drs. Ogino and Knaus and it is also referred to as the "Ogino-Knaus" or the "rhythm" method.

The Standard Days Method (SDM) is a new and simplified Calendar-based method. Instead of observing and tracking the length of your menstrual cycles, you assume that there's a fixed period of fertility ("standard rule") from Day 8 to Day 19 of your cycle (regardless of the length of your cycle). Thus, you abstain (or use a barrier method) during that interval.

CycleBeads is a string of color-coded beads that represent a woman's menstrual cycle. Each bead represents a day of the cycle and the color helps you determine if you're likely to be fertile that day. Think of CycleBeads as a "visual aid" for the SDM method. According to its developer, the 1st year failure rate is 5% with perfect use, and 12% with typical use.

b) Basal Body Temperature (BBT) Method

(Bioself 110/Mini-Sofia, LadyComp/BabyComp, Cyclotest-2)

With the Basal Body Temperature (BBT) method you attempt to predict the end of the fertile period by observing the changes in the BBT. (BBT refers to the resting core body temperature.) The probable 1st year failure rate is 20% with typical use, and 2% with perfect use.

A number of "computerized thermometers" have been developed to be used in conjunction with BBT. Briefly, this is how they work: you measure your BBT in the usual manner and then you enter those measurements, together with information about your cycle length, into the device (instead of charting it on the graph paper). The device then displays an indicator light for the fertile period of the cycle.

The efficacy information for these devices is scant. One study found a 9% failure rate for Bioself, but the women using it were already experienced in using FAMs. The only data on the failure rates of Ladycomp/Babycomp is based on an observational study (5.3% failure after 1st year, 6.8% after 2nd year, and 8.2% after 3rd year). (This type of study is not reliable enough and can not be compared with the more exact studies used for other bc methods.) Cyclotest-2 probably has an efficacy similar to Bioself, but more studies are needed to confirm all these rates.

c) Ovulation Method

Billings Method (Cervical Mucus)

Creighton Model

TwoDay Method

The Ovulation method attempts to identify the start of the fertile period, by observing and tracking the changes in the quality and quantity of the cervical secretions. It is also called the "Billings" method (after the physicians who first described it), or the "Cervical Mucus" method (cervical mucus is another name for cervical secretions). The 1st year failure rate is about 40% with typical use, and 3% with perfect use.

The Creighton Model method is a variation of the ovulation method. It is a standardized educational program in which you are taught when you are most likely to ovulate based on observations of cervical secretions (just like the ovulation method). In addition, you are taught to monitor if your reproductive system is functioning normally or abnormally, based on observations of several biomarkers (e.g., breast tenderness, abdominal discomfort, vaginal discharges, etc.). According to its proponents, the 1st year failure rate is about 17% with typical use, and 1% to 4% with perfect use.

The TwoDay method is a new and simplified ovulation method. Instead of sampling, observing, and tracking the changes in your cervical secretions, you only need to observe if secretions are present or absent. "Secretions" are defined as anything that you perceive coming from the vagina, except menstrual bleeding. The estimated 1st year failure rate is 3% with perfect use.

d) Cervical Changes Method

This method attempts to identify the fertile period by observing and tracking the changes in the consistency and position of the cervix. Rarely used alone, this method is usually used in combination with other indicators, like BBT and/or cervical secretions.

e) Sympto-Thermal Method

This method attempts to identify the start and the end of the fertile period by using several indirect fertility indicators (cervical secretions, cycle length, BBT) simultaneously. The 1st year failure rate is between 4.9% and 34.4%, with a mean of 16%, with typical use, and 2% with perfect use.

f) Personal Hormone Monitoring Method

Persona

This method identifies the fertile period by measuring urinary hormone levels. This is the only FAM which uses a direct indicator (urinary levels of estrogen and luteinizing hormone) to determine the fertile period. Persona, a personal hormone monitoring device, has a 1st year failure rate of 6.2% with perfect use (according to its manufacturer).

Note: ClearPlan and Persona are manufactured by the same company. However, ClearPlan is a Fertility Monitor, not a birth control method and should not be used as such.


* Natural Family Planning part I and II.

ETA: Despite my conviction that I know how to indent the text came out looking funny so I changed it back to normal.